JP2002048247A - Sealing device enabling detection of rotation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sealing device which enables rotation to be detected with improved accuracy and high reliability. SOLUTION: The sealing device is provided with an annular part 6, which is fit into a fitting surface D (peripheral surface) of a shaft 1, and a rubber part 5 (encoder) which has parts to be detected by a sensor 3, located in peripheral direction. The rubber part 5 is placed against the fitting surface D of the shaft 1, to which the annular part 6 is fit, with a clearance in the peripheral direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device used for, for example, a shaft sealing portion of various devices, and more particularly to a sealing device capable of detecting rotation of two members that rotate relative to each other.

[0002]

2. Description of the Related Art Conventionally, as this kind of sealing device, for example, a vehicle speed sensor for detecting a vehicle speed of an automobile has been used. A rotor is mounted, and an induction current type sensor is arranged close to the rotor. An induction current is generated by rotating the rotor and cutting off the magnetic flux of the sensor, thereby detecting a rotation speed.

[0003] However, such a device requires a dedicated space for mounting the rotor and the sensor, and the rotor and the sensor are provided separately from a sealing device for sealing the bearing. It has become.

Therefore, as shown in FIG. 4A, a sealing device in which a rotor and a sensor are integrated has been proposed.

[0005] This is because an annular member 56 fitted to the shaft 51 is used.
, A rubber member 55 formed by baking on the annular member 56, an annular member 58 fitted on the housing 52, and a rubber member 57 formed by baking on the annular member 58.

As shown in FIG. 3, the rubber member 55 has a plurality of magnetic poles so that magnetic poles NS are alternately arranged in the circumferential direction. The change in magnetization is detected by a sensor 53 such as a magnetoresistive element. Thus, the rotation speed and the like are detected.

The rubber portion 57 has a lip to suppress dust from outside and grease from flowing inside.

[0008]

However, in the case of the prior art described above, a fitting margin L1 is provided between the shaft 51 and the multi-pole rubber member 55. When the annular member 56 is fitted to the shaft 51, a phenomenon occurs in which the rubber material 55 rises (I ″ in FIG. 4A).
Section), there is a possibility that an error in rotation detection may occur due to disturbance of the magnetic force.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a highly reliable rotation detecting sealing device with improved rotation detection accuracy. To provide.

[0010]

In order to achieve the above object, according to the present invention, an annular gap between two members provided coaxially and rotatably relative to each other is sealed, and the relative space between the two members is reduced. What is claimed is: 1. A sealing device capable of detecting rotation, wherein rotation is detectable, comprising: an annular member fitted to a peripheral surface of one of said two members; An elastic member having a portion to be detected which is provided and detected by the detecting means, and the peripheral surface of one of the two members to which the annular member is fitted and the elastic member are arranged in a circumferential direction. Characterized by being provided apart from each other.

Thus, even if the annular member is fitted on the peripheral surface of the one member, the elastic member does not come into contact with the peripheral surface of the one member. Without, the property of the detected portion of the elastic member does not change, especially errors due to the radial position is less likely to occur, it is possible to increase the detected portion detected by the detection means,
The rotation detection accuracy can be improved.

The detected part of the elastic member has multiple poles,
It is also preferable that the relative rotation of the two members can be detected by a change in magnetization generated from a detected portion of the multi-pole elastic member.

Accordingly, even when the rotation is detected by the magnetic detecting means, the elastic member does not rise and the property of the multi-pole detection portion of the elastic member does not change, so that the magnetic force is not disturbed. Therefore, the magnetic force can be stabilized, and highly accurate detection can be performed.

[0014]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, and relative arrangement thereof should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions, and are not intended to limit the scope of the invention to the following embodiments.

(Embodiment 1) FIG. 1 is a schematic sectional view of a sealing device capable of detecting rotation according to Embodiment 1 of the present invention.

The sealing device capable of detecting rotation seals an annular gap between a housing 2 as two members provided coaxially and relatively rotatably and a shaft 1 inserted into a shaft hole of the housing 2. , Fitting surface D as a peripheral surface of shaft 1
A rubber member 5 (encoder) serving as an elastic member having a detected part which is formed by baking the annular member 6 and has a multi-pole structure, and a fitting surface E of the housing 2.
And a rubber member 7 formed by baking the annular member 8.

The rubber material 5 is made of a magnetizable rubber material in which, for example, ferrite (iron) is dispersed. As shown in FIG. 3, the rubber material 5 is formed into a multi-pole magnetic material such that magnetic poles NS are alternately arranged in the circumferential direction. Then, it is formed by baking on a radial portion 6b constituting an annular member 6 fitted to the shaft 1, and a change in magnetization generated from the rotating rubber material 5 is sensed by a sensor 3 such as a magnetoresistive effect element. Is detected.

The rubber member 7 formed by baking the annular member 8 is made of a rubber-like elastic material, and the radial portion 8b constituting the annular member 8 has a cylindrical portion 6a constituting the annular member 6.
A sealing portion 7a that slides on the outer peripheral surface of the
A seal portion 7b that slides on the radial portion 6b of the annular member 6 to seal in the radial direction is provided. As a result, it is possible to suppress the outflow of dust and grease from the outside.

The sealing device according to the present embodiment seals a bearing portion, and reference numeral 4 denotes a bearing.

Here, as a characteristic configuration of the present embodiment, the rubber member 5 is provided in the circumferential direction apart from the fitting surface D as the peripheral surface of the shaft 1, that is, 1, a gap L2 is provided.

By providing this gap L2, the phenomenon that the rubber material bulges (the portion I "in FIG. 4 (a)) which has occurred at the time of fitting as in the prior art does not occur (I in FIG. 1). Part).

Since the rubber material 5 does not rise, the surface facing the sensor 3 is always flat without being deformed, and errors due to the position of the sensor 3, especially in the radial direction, are less likely to occur.

Therefore, the detection surface of the rubber material 5 detected by the sensor 3 can be enlarged, and the magnetic force can be stabilized without disturbing the magnetic force.
The accuracy of the sensor 3 can be improved.

Further, by providing the gap L2 between the rubber material 5 and the shaft 1 close to each other, sealing performance can be obtained.

Further, by setting the length of the cylindrical portion 6a fitted on the fitting surface D of the shaft 1 to a predetermined length, it is possible to prevent the annular member 6 and the rubber material 5 from being shaken by the rotation of the shaft 1. Since it can be prevented, stable and accurate detection becomes possible.

Conventionally, as shown in FIGS. 4 (b) and 4 (c), it is difficult to control the positioning in the axial direction when the sealing device is fitted, and the axial position C ″ of the rubber material 55 shifts. Because of the possibility, the positions of the rubber member 55 and the sensor unit 53 are not fixed, and the accuracy of rotation detection may be reduced.

Therefore, in this embodiment, steps F and G for positioning the sealing device are provided on the shaft 1 and the housing 2.

That is, the annular member 8 is provided on the housing 2.
Is provided at the R portion between the cylindrical portion 8a and the radial portion 8b, and the shaft 1 is provided with an annular member 6;
A step F positioned at the tip of the cylindrical portion 6a is provided.

The axial position of the sealing device is accurately determined by the steps F and G (for example, the end face B of the housing 2).
Can be set so that the end surface C of the rubber member 5 is located at a position of a distance H2 from the sensor 3). .

Even when the rubber material 5 is thickened in the axial direction due to the increase in the magnetic material and the springback is large, the axial position is not shifted by the axial positioning by the steps F and G. The position management in the axial direction of the rubber material 5, which has been difficult to achieve, that is, the driving management becomes easy, and the workability can be improved and the detection accuracy by the sensor 3 can be improved.

Further, since the position between the annular members 6 and 8 is also determined, the sealing portion 7a surely makes sealing contact with the outer peripheral surface of the cylindrical portion 6a, and the sealing portion 7b seals with the radial portion 6b with a predetermined sealing pressure. Since the contact can be made, the sealing performance of the sealing device can be exhibited.

(Embodiment 2) FIG. 2 is a schematic sectional view of a sealing device capable of detecting rotation according to Embodiment 2 of the present invention.

The sealing device according to the present embodiment includes an annular member 18 fitted on the peripheral surface of the rotating member 12 and an annular member 18.
A rubber member 15 serving as an elastic member having a detected part which is multi-polarized is formed on the shaft member 11 which is formed by baking on the tip of a radial portion 18b constituting the annular member 18 and is fixed. And a sealing portion 17 that moves and makes sealing contact.

The rubber material 15 is made of, for example, a magnetizable rubber material in which ferrite (iron) is dispersed. As shown in FIG. 3, the rubber material 15 is multi-polarized so that magnetic poles NS are alternately arranged in the circumferential direction. A change in magnetization generated from the rotating rubber member 15 is sensed by a sensor 13 such as a magnetoresistive element, which is formed by baking on an annular member 18 fitted to the rotating member 12, and the rotation speed and the like are detected.

Further, the seal portion 17 formed by baking the annular member 18 is made of a rubber-like elastic material, so that dust from outside and grease inside can be suppressed.

The sealing device according to the present embodiment seals a bearing portion, and 14 denotes a bearing.

Here, as a characteristic configuration of the present embodiment, the rubber member 15 is provided in the circumferential direction at a distance from the fitting surface E 'as the peripheral surface of the rotating member 12, that is, , A gap L2 is provided for the rotating member 12.

By providing this gap L2, the phenomenon that the rubber material bulges up at the time of fitting (I portion in FIG. 4 (a)) unlike the prior art does not occur (I in FIG. 2). 'Department).

Since the rubber material 15 does not bulge, the surface facing the sensor 13 is always flat without deformation, and errors due to the position of the sensor 13, particularly in the radial direction, are less likely to occur.

Therefore, the detection surface of the rubber material 15 detected by the sensor 13 can be enlarged, and the magnetic force can be stabilized without disturbing the magnetic force, so that the accuracy of the sensor 13 can be improved. It becomes possible.

Further, by providing the gap L2 between the rubber member 15 and the rotating member 12 close to each other, sealing performance can be obtained.

Further, by setting the length of the cylindrical portion 18a fitted on the fitting surface E 'of the rotating member 12 to a predetermined length, the annular member 18 and the rubber material 15 are rotated by the rotation of the rotating member 12. Since blurring can be prevented, stable and accurate detection becomes possible.

Conventionally, as shown in FIGS. 4 (b) and 4 (c), it is difficult to control the positioning when fitting the sealing device, and there is a possibility that the axial position C "of the rubber material 55 is shifted. Therefore, the positions of the rubber member 55 and the sensor unit 53 are not fixed, and the accuracy of rotation detection may be reduced.

Therefore, in the present embodiment, the rotating member 12
Is provided with a step G ′ for positioning the sealing device. The step G ′ positions the annular member 18 at the tip of the cylindrical portion 18a.

The position of the sealing device in the axial direction is accurately determined by the step G '(for example, the end surface B' of the rotating member 12).
Can be set so that the end surface C ′ of the rubber member 15 is located at a distance H2 from the sensor 13), so that the position of the end surface C ′ of the rubber member 15 with respect to the sensor 13 is constant, and the detection accuracy of the sensor 13 is improved. Can be.

Even in the case where the rubber material 15 becomes thicker in the axial direction due to the increased amount of the magnetic material and the springback is large, the axial position is not shifted by the axial positioning by the step G '. It is easy to manage the position of the rubber member 15 in the axial direction, which is difficult, that is, it is easy to manage the driving.

With the sealing device according to the present embodiment, the sealing performance can be exhibited even in a small space, and the rotation detection accuracy can be improved.

[0048]

As described above, according to the present invention,
Since the peripheral surface of one of the two members to which the annular member is fitted and the elastic member are spaced apart in the circumferential direction, the elastic member comes into contact with the peripheral surface of the one member. Since the elastic member does not swell, the error due to the position in the radial direction is less likely to occur, and the detected portion detected by the detecting means can be increased.
The rotation detection accuracy can be improved.

Further, even when the rotation is detected by the magnetic detecting means, the elastic member does not rise and the property of the multi-pole detection portion of the elastic member does not change, so that the magnetic force is not disturbed. The magnetic force can be stabilized, and highly accurate detection can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a sealing device according to Embodiment 1 of the present invention.

FIG. 2 is a schematic sectional view of a sealing device according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating an elastic member that has been made multi-magnetic, as viewed from the direction of arrow A in FIGS.

FIG. 4 (a) is a schematic sectional view of a conventional sealing device, and FIGS. 4 (b) and 4 (c) are views showing a state where the mounting device is displaced in an axial direction.

[Explanation of symbols]

 1 shaft 2 housing 3,13 sensor 4,14 bearing 5,15 rubber material (encoder) 6,8,18 annular member 6a, 8a, 18a cylindrical part 6b, 8b, 18b radial part 7 rubber material 7a, 7b, 17 seal part 11 shaft-like member 12 rotating member

Claims (2)

[Claims] 1. A rotation-detectable sealing device which seals an annular gap between two members provided rotatably relative to each other coaxially and enables detection of relative rotation of the two members. An annular member fitted on the peripheral surface of one of the members, and an elastic member provided on the annular member, the elastic member having a detected portion disposed in the circumferential direction and detected by the detecting unit. A sealing device capable of detecting rotation, wherein a peripheral surface of one of the two members to which the annular member is fitted and the elastic member are provided apart from each other in a circumferential direction. . 2. The detection part of the elastic member has multiple magnetic poles,
2. The sealing device according to claim 1, wherein relative rotation between the two members can be detected by a change in magnetization generated from a detected portion of the multi-pole elastic member.